Technical Field
The present invention relates to a technique used in construction work, civil engineering work, and the like.
Background Art
For example, at a construction site, work of marking plural reference positions is conducted based on a construction drawing. The marking work is conducted not only at the construction site, but also at a civil engineering worksite. These reference positions are called “survey setting points”. Various kinds of construction works are conducted using the survey setting points as references. For example, in a case of interior finishing work in a building, locations of wall materials, locations of electric wiring, locations of air conditioners, locations of various types of piping, etc. are determined using plural survey setting points marked on a floor surface as references.
Meanwhile, the marking work for the survey setting points is performed by measurement using a total station. In this process, measuring light from the total station is received by a dedicated reflective prism, and the location of the mark is identified. For example, a mark or the like is placed at a survey setting point in the case of a construction site, and a pile is driven at a survey setting point in the case of a civil engineering worksite.
In the process of identifying the location of a survey setting point, a worker walks holding a reflective prism in the hands while watching the survey setting point in a guide display indicated on a terminal display. Then, the worker temporarily places the reflective prism at the location displayed on the terminal display and receives the measuring light from the total station at the reflective prism. The total station detects the measuring light reflected by the reflective prism and performs calculations such as of margin of error, whereby a precise location of the survey setting point is calculated. This information is displayed on the terminal of the worker, and then the worker finely adjusts the location of the reflective prism. The location of the survey setting point is identified by alternately repeating these steps, and it is then marked.
In the step of finely adjusting the location of the prism, the reflective prism must be finely moved with a precision of not more than a centimeter in a condition in which the reflective prism attached with a rod-shaped pin is vertically erected. At this time, if the reflective prism tilts, the precision of the survey is decreased, and the margin of error is increased. As a technique for solving this problem, a technique disclosed in U.S. Unexamined Patent Application Publication No. 2012/0010847 is publicly known.
According to the technique disclosed in U.S. Unexamined Patent Application Publication No. 2012/0010847, a reflective prism is arranged on an X-Y stage, which can finely move in the X-axis direction and in the Y-axis direction that orthogonally cross each other, and it thereby can be finely moved in the X-axis direction and in the Y-axis direction without tilting.
However, in the technique disclosed in U.S. Unexamined Patent Application Publication No. 2012/0010847, the movable direction is limited to the two axis directions that orthogonally cross each other. Therefore, the reflective prism can be moved straight to a target position as long as the target position is on the X-axis or the Y-axis of the X-Y stage. Otherwise, the reflective prism must be moved on the X-axis of the X-Y stage and then be further moved on the Y-axis. Such a step is complicated and tends to increase the margin of error.